FI Charts (T120+ onwards) Winter 2018 **READ MOD NOTE IN FIRST POST**

Meteorite58

I know I shouldn't but what oh the heck !

Putting this here so as to track the models to see how they perform and to learn ! No Expert and this could change. Going by the present GFS runs to me looking very cold next week end. Northern counties could be seeing wintry precipitation and a fair shot of snow perhaps Fri, Sat and Sun. Mountains look like getting a good dusting and maybe further down if those temperatures hold. Lp Pressure forming as it passes W of Scotland on a NE'ly track ( showing this for a few runs now ) initially bringing down frontal precipitation mixing with very cool air followed by convective precipitation I would imagine. Possibly Thunder type set up also ? Sharp frosts possible at night and temps possibly staying down round 5-10C

ECM showing a very cold set up also but not showing the development of a LP like the GFS at this stage but hinting at developing a wave depression. What it does show from previous runs is an area of LP deepening off the S coast as it tracks across the UK.

Meteorite58

MJohnston wrote: »

Just a quick question Meteorite - is there any analysis on which of the models is more reliable for this kind of system?

Not sure MJohnston. Maybe somebody else could shed some light on it.

Meteorite58

The Jet coming out of Canada/Greenland next weekend.

Meteorite58

Nice chart showing the route of the winds and the Jet . That is some amount of cold air advection out of Greenland and the 528 dam line showing the snow potential.

sideswipe

Winter 2017/18 HERE.......WE........GO......

BLIZZARD7

GFS and ECM showing next weekend will be very chilly with a good chance of Hill snow and possibly to lower levers, especially further north.

UKMO showing a very different pattern but seems isolated in its position as of now, although still chilly at the surface.

Meteorite58

Latest runs see the ECM and the GFS looking closer together. Beginning to see more windy weather towards the end of the Week with a deep area of LP coming straight out of Greenland bringing down polar maritime followed by polar air I think and early indications of some spectacular wind chill for this time of year.

Could remain quite cold with frosty nights for a couple of days after next week end .

Latest ECM run showing cold NE'ly winds probably late Sun early Mon. No doubt will be of interest to those living on the East of the country.

Meteorite58

Latest ECM run showing Ireland under a slack area of HP Tues 28th with a very sharp severe frost. Plenty of twists and turns to come but the trend is certainly looking cold.

Meteorite58

IMO,over the last few runs the models are backing off anything significant going into next weekend. ECM has HP building over Ireland by the end of next weekend and for the following few days which could lead to frosty ( possibly very cold ) nights and presumably cooler temperatures on the E of the country.

No Storms or anything too windy in sight at present.

NW, N, NE aspect to the airflow at some stage over the weekend ( Sat, Sun, Mon ) but not looking as cold during the day as earlier runs.

Still showing widespread -4 C 850 hPa Temperatures over the coming week and beyond, 500 hPa Temps not as cold as earlier runs decreasing the chances of snow yet still a chance of getting some wintry precipitation in Northern counties over the weekend.

Floki

This is FI after all and this is way into the FI.

Are we going to see the High Pressure record broken?

Meteorite58

Floki wrote: »

This is FI after all and this is way into the FI.

Are we going to see the High Pressure record broken?

Just shows you how much the models are changing day by day of late granted the 29th is over two weeks away.

Meteorite58

The main models all showing LP around Weds/ Thurs next week. This could be the catalyst for the introduction of a spell of colder / wintry weather as the area of LP phases with LP from Northern regions. Or maybe not

ninebeanrows

It is that time of year where we get some hopeful charts that remind us of 2010 and just what 'could' happen. Over the last two days I have been keeping an eye on developments up north and I must say there are encouraging signs......of as per usual the ensembles show basically zero risk of a cold incursion...but let that not worry us...we know from the past the ensembles are useless in this situation....

Things can change rapidly...watch this space.... :O

ninebeanrows

GEM

@ 156

Donegal Storm

Nice GFS run just now, big Atlantic block next week drawing in north easterlies. Wildly different solutions on every run though so a lot of uncertainty in the short/medium term



Edit: November 2010 for comparison!

ninebeanrows

Things do seem to be merging together now - if this did happen would again seriously undermine the value of medium term ensemble weather data in these situations...

++As simply no solution illustrated the above outcome yesterday/ 2 days ag0++

Ensembles are a fantastic tool - but should not be treated as the entire suite of possible solutions...

Gonzo

Trying my best to hold back the excitment but those charts spell bad news for mild and rain across the north and eastern side of the country.:)

Donegal Storm

Nov 2010 was probably a one in 100 year event, the chances of it happening twice in a decade are surely close to nil. Fairly spectacular run though with the block reloading and strengthening and the jet over the Canaries!

For what it's worth, the euro model is showing raging SW'erlies again next week which naturally is a lot more likely

BLIZZARD7

November 2010 Redux on the 18z GFS tonight, 12z GEM also very good. Hopefully this is a trend that continues in the morning, I expect lots more flip flopping but this isn't really all that far away, 7-8 days from the start of potentially epic winter weather... Or a mild South westerly.

icesnowfrost

It's tantalising viewing but it does look like around the 23rd to 25th a north or northeasterly is trying to break through.
Hopefully the models can get a hold of what's going on.

squarecircles

icesnowfrost wrote: »

It's tantalising viewing but it does look like around the 23rd to 25th a north or northeasterly is trying to break through.
Hopefully the models can get a hold of what's going on.

Gfs 12z says NO.

km79

squarecircles wrote: »

Gfs 12z says NO.

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snowstorm445

We all know the nature of these things. If every cold scenario that was modeled over the season verified we’d be in the freezer for most of the winter.

I would only consider a cold event to be slightly probable if it is forecasted within about 5 days, even then 3 days is probably when it becomes a 50-50 affair. Always best to be sceptical.

Meteorite58

The jet charts taking a more Southern route and seem to be powering up at the end of next week which would correspond with seeing LP systems developing and some look like becoming quite deep and no doubt would contain plenty of rain and windy conditions ( met Eireann already mentions a lot of wet days for next week from Tues on including spot flooding for Weds ), could be seeing high rainfall totals as the week goes on .

Almost reluctant to say that I think the models are more in alignment atm.

sryanbruen

Wouldn’t be a classic GFS FI without a chart like this.

GFS 18z +252hrs:





The ECM 12z is very similar at +240hrs but blocking is much weaker and the low pressure is centred to the north and northeast of Scotland than Scandinavia here allowing for more zonal northwesterly conditions rather than straight northerlies:

Meteorite58

Adding to the charts posted by sryanbreun ,the ECM goes on to develop a large are of LP over N Europe bringing in those much coveted E'lys with what seems like a block developing in the Atlantic. Not a particular cold set up yet but leading in the right way for the cold lovers I would think. Long way off and as we have seen the models flip flopping daily but at some stage they will come right

sryanbruen

Ah GFS you just don't stop :pac::

sryanbruen

After a mild start to the week, next weekend is looking quite chilly with clear cut northwesterlies and lots of showers. Temperatures well and truly into the single figures by Saturday. Dare I say it, chance of wintry showers in the north with the kind of temperatures the models are showing.

Here's the GFS 06z for Saturday (+120hrs):



After the weekend, the GFS 06z shows quite an extended spell of anticyclonic weather for Ireland albeit with some moderation at times with fronts pushing down from the north. Winds mostly coming from the northwest with the high pressure going in circles throughout the run out to the west of Ireland. All the while though, a very stubborn block of high pressure over Greenland!



ECM 00z is very similar for this weekend. In fact, looks like a carbon copy of the GFS 06z.



After this, mostly cool and dry 'til day 10, Thursday, Nov 30th when the high pressure starts to build more over Ireland than the Atlantic.

sryanbruen

The agreement tonight with the models is astonishing :eek:. It's been a long time since I've seen agreement on cold such as this as well as the fact that there have been so many upgrades on cold this month.

GFS 12z: (literally no different from the 06z)





UKMO 12z: (pretty much the same as the GFS 06z & 12z)



GEM 12z:

BLIZZARD7

The stuff dreams are made of